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Volume 39 (2014)
- Issue 2 Pages 93-
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Volume 39, Issue 2
Displaying 1-4 of 4 articles from this issue
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Yuji Chikashige, Miho Yamane, Kasumi Okamasa, Chie Mori, Noriko Fukuta ...Article type: Full article
2014 Volume 39 Issue 2 Pages 93-100
Published: 2014
Released on J-STAGE: July 23, 2014
Advance online publication: June 20, 2014JOURNAL FREE ACCESS FULL-TEXT HTML
Supplementary materialIn meiosis, pairing and recombination of homologous chromosomes are crucial for the correct segregation of chromosomes, and substantial movements of chromosomes are required to achieve homolog pairing. During this process, it is known that telomeres cluster to form a bouquet arrangement of chromosomes. The fission yeast Schizosaccharomyces pombe provides a striking example of bouquet formation, after which the entire nucleus oscillates between the cell poles (these oscillations are generally called horsetail nuclear movements) while the telomeres remain clustered to the spindle pole body (SPB; a centrosome-equivalent structure in fungi) at the leading edge of the moving nucleus. S. pombe mutants defective in telomere clustering frequently form aberrant spindles, such as monopolar or nonpolar spindles, leading to missegregation of the chromosomes at the subsequent meiotic divisions. Here we demonstrate that such defects in meiotic spindle formation caused by loss of meiotic telomere clustering are rescued when nuclear movement is prevented. On the other hand, stopping nuclear movement does not rescue defects in telomere clustering, nor chromosome missgregation even in cells that have formed a bipolar spindle. These results suggest that movement of the SPB without attachment of telomeres leads to the formation of aberrant spindles, but that recovering bipolar spindles is not sufficient for rescue of chromosome missegregation in mutants lacking telomere clustering.View full abstractDownload PDF (5913K) Full view HTML -
Ryuichiro Kurata, Sugiko Futaki, Itsuko Nakano, Atsushi Tanemura, Hiro ...Article type: Full Article
2014 Volume 39 Issue 2 Pages 101-112
Published: 2014
Released on J-STAGE: October 08, 2014
Advance online publication: September 05, 2014JOURNAL FREE ACCESS FULL-TEXT HTML
Supplementary materialStem cells routinely maintain the main epidermal components, i.e. the interfollicular epidermis, hair follicles, and sweat glands. Human sweat glands present throughout the body are glandular exocrine organs that mainly play a role in thermoregulation by sweating. Emerging evidence points to the presence of stem cells in sweat glands, but it remains unclear whether such stem cells exist in human sweat glands. Here, we attempted to gather evidence for stem cells in human sweat glands, which would be characterized by self-renewal ability and multipotency. First, we explored human sweat gland cells for expression of stem cell markers. CD29 and Notch, epidermal stem cell markers, were found to reside among α-smooth muscle actin-positive myoepithelial cells in human sweat glands. Next, sweat gland myoepithelial cells were isolated from human skin as a CD29hiCD49f hi subpopulation. The myoepithelial cell-enriched CD29hiCD49f hi subpopulation possessed the ability to differentiate into sweat gland luminal cells in sphere-forming assays. Furthermore, CD29hiCD49f hi subpopulation-derived sphere-forming cells exhibited long-term proliferative potential upon multiple passaging, indicating that the CD29hiCD49f hi myoepithelial subpopulation includes stem cells with self-renewal ability. These findings provide evidence that human sweat gland myoepithelial cells contain stem cells that possess both self-renewal ability and multipotency to differentiate into sweat glands.View full abstractDownload PDF (1430K) Full view HTML -
Kazushige Morishita, Fumito Ozasa, Koichi Eguchi, Yasuhide Yoshioka, H ...Article type: Full-Article
2014 Volume 39 Issue 2 Pages 113-124
Published: 2014
Released on J-STAGE: December 05, 2014
Advance online publication: October 11, 2014JOURNAL FREE ACCESS FULL-TEXT HTMLThe dedicator of cytokinesis (DOCK) family proteins that are conserved in a wide variety of species are known as DOCK1–DOCK11 in mammals. The Sponge (Spg) is a Drosophila counterpart to the mammalian DOCK3. Specific knockdown of spg by pannir-GAL4 or apterous-GAL4 driver in wing discs induced split thorax phenotype in adults. Reduction of the Drosophila c-Jun N-terminal kinase (JNK), basket (bsk) gene dose enhanced the spg knockdown-induced phenotype. Conversely, overexpression of bsk suppressed the split thorax phenotype. Monitoring JNK activity in the wing imaginal discs by immunostaining with anti-phosphorylated JNK (anti-pJNK) antibody together with examination of lacZ expression in a puckered-lacZ enhancer trap line revealed the strong reduction of the JNK activity in the spg knockdown clones. This was further confirmed by Western immunoblot analysis of extracts from wing discs of spg knockdown fly with anti-pJNK antibody. Furthermore, the Duolink in situ Proximity Ligation Assay method detected interaction signals between Spg and Rac1 in the wing discs. Taken together, these results indicate Spg positively regulates JNK pathway that is required for thorax development and the regulation is mediated by interaction with Rac1.View full abstractDownload PDF (1138K) Full view HTML -
Hiroki Moritomo, Kengo Yamada, Yuki Kojima, Yasutaka Suzuki, Seiji Tan ...Article type: Full-Article
2014 Volume 39 Issue 2 Pages 125-133
Published: 2014
Released on J-STAGE: December 05, 2014
Advance online publication: October 16, 2014JOURNAL FREE ACCESS FULL-TEXT HTMLHere we describe the design and synthesis of a bifunctional two-photon fluorescence probe, N,N'-dimethyl-4,4'-(biphenyl-2,1-ethenediyl)dipyridinium hexafluorophosphate (BP6). HeLa, Hek293, and Paramecium caudatum cells were stained with BP6. BP6 accumulated on the mitochondria of all three cell types when the mitochondrial membrane potential was high. As the mitochondrial membrane potential decreased following the addition of carbonyl cyanide m-chlorophenyl hydrazine, BP6 moved from the mitochondria to the nucleus in a reversible manner, depending on the mitochondrial membrane potential status. The maximum value of the two-photon absorption cross-section of BP6 is 250 GM (1 GM=1×10–50 cm4 s molecules–1 photon–1). This value is 3 and 30 times larger, respectively, than that of the conventional mitochondria selective probes, rhodamine 123 and green fluorescence protein. These results suggest that BP6 should be useful for monitoring mitochondrial membrane potential by two-photon excitation.View full abstractDownload PDF (863K) Full view HTML
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